The furnace and crucible are normally disposed in a pit and a casting machine moves laterally relative to the pit to position the mold over the crucible. The casting machine typically includes a vertically movable platen which opens and closes the mold for repetitive casting of metal parts. The casting machine is supported on a carriage for movement away from the crucible for changing molds or servicing the furnace, each mold comprising a lower drag and an upper cope. When the casting machine is positioned away from the crucible or over the crucible, the mold is loaded onto the movable platen with the drag and cope banded together. Thus, the drag is banded to the cope and is held thereto as the cope is attached to the movable platen. Alter the cope is secured to the movable platen, the movable platen is lowered to rest the drag upon a base plate of the machine. The banding is removed and the drag is secured to the base plate. The carriage includes a lilt system for supporting the entire weight of the casting machine on the crucible for sealing the base plate to the crucible whereby the molten metal bath may be pressurized under the base plate. Thereafter the mold cavity defined by the drag and cope are opened and closed for repetitive casting of a series of parts.
In a relatively large casting assembly supporting a very large mold to cast very large parts, it frequently occurs that, upon opening of the mold to remove the cast part, the cope sticks to the part, but only on one side of the part, thereby creating a resistance force between the cope and drag which is asymmetrical to the central vertical axis. This asymmetrical force causes the cope and, consequently, the movable platen to cock relative to horizontal causing binding and wear between the guide posts and the movable platen slidably supported thereon. The larger the casting assembly; i.e., the larger the mold, the greater the potential for a long lever arm between the central axis and an asymmetrical force to thereby produce very large cocking and binding forces.